I used to include "The Moon is a Harsh Mistress" in a Science Fiction course I taught. I just checked my records and the last time I taught the course was 1986. But the other story, if I remember it rightly, was much earlier, back in the early Heinlein days. I first started reading Heinlein, Asimov, and Clarke back in the late 40s and early 50s.
Got me beat - I wasn't born unti 1962! LOL
I believe that "The Moon is a Harsh Mistress" is the best Science Fiction books ever written in the category of "Not part of a trilogy". A couple of asimov's robot books, and Dune repersent close seconds ("trilogy" came much later) in that category. I would love to hear your other candidates.
TANSTAAFL, I was always under the impression, came from the book, but perhaps it appeared in some earlier work.